Static stretching is unlikely to improve strength and performance
A debate has arisen in the past few years that static stretches can actually reduce strength. It depends on how it's used.
Q: Is it true that static stretching improves performance and prevents injury?
The science
We see it all the time — people lacing their fingers and pulling their arms behind their bodies to stretch their biceps or sitting on the ground and reaching for their toes to stretch their hamstrings before a workout or sports competition.
While stretching can help prepare the body for exercise and athletics, the type and duration are key, experts said. Static stretching — holding a specific pose typically for a period of seconds to stretch the muscles — has been under debate for a long time, as some research has suggested that under certain circumstances, it may have negative effects, including reducing maximal strength and power.
Performance effect: Static stretching is not really intended to enhance strength or power, and in recent years, there have been studies suggesting the opposite, leading to widespread debate over whether it should be incorporated into warm-up routines.
A 2019 literature review reported, however, that while static stretches of a single muscle group lasting longer than 60 seconds may negatively affect strength and power performance, stretching for less than 60 seconds has little such risk. Similarly, a 2021 review noted that appropriate durations of static stretching as part of a warm-up, which includes aerobic activities, for instance, have "trivial effects" on performance.
At the same time, static stretching can help increase range of motion, and for athletes who rely heavily on their flexibility, such as gymnasts, dancers, and martial artists, static stretching may improve their overall performance, experts said.
“If you come out of the locker room and go straight onto the track and try to clear hurdles, you’re going to be clipping a lot of hurdles because you haven’t got the range of motion yet to clear that height,” said Malachy McHugh, director of research at the Nicholas Institute of Sports Medicine and Athletic Trauma at Northwell Health. “In many sports, you need to do some stretching before you take the field of play so that you have the range of motion required to perform effectively.”
Injury prevention: There is not a clear consensus on whether stretching reduces injury risk, possibly because different sports have different physical requirements, some researchers have suggested.
Many experts believe that while stretching does not prevent all types of injuries, it may help prevent muscle injuries by shifting the muscle to a longer operating length, McHugh said.
“That in itself is probably beneficial for preventing muscle strains because it means when your muscle is out in a lengthened position where it might be at risk of tearing, you're actually stronger and you're able to resist the forces and protect the muscles from getting torn,” he said.
Stretching should be incorporated into a comprehensive warm-up routine not only for physical preparedness but also for mental readiness, some experts said. Tony Kay, professor of biomechanics at the University of Northampton, said he would recommend a warm-up that also includes cardiovascular work and task-specific drills, "as this can prepare the body but also the mind for the athletic task ahead," making the athlete feel better prepared.
What else you should know
Stretching needs vary, depending on the person and activity, but the American College of Sports Medicine (ACSM) and sports medicine experts offer some general guidelines:
-Perform flexibility exercises or stretches daily, or at least two to three times per week, the ACSM recommends.
-Stretch muscles until they feel tight or slightly uncomfortable, but not painful, and hold for 10 to 30 seconds. Older adults may achieve greater flexibility with longer stretches lasting 30 to 60 seconds, the ACSM said. The activity is also important. If your performance is strength-dependent, short-duration stretches are okay to include, but do not stretch a single muscle more than 60 seconds, as this longer duration can impair maximal strength performance, Kay said.
-Be consistent. If stretching is part of your normal warm-up routine, continue. Likewise, if you do not usually stretch before a workout or a run, then don’t. “Inconsistent warm-ups can lead to greater injury risk,” Kay said.
-Never stretch an injured muscle.
The bottom line
While static stretching is not likely to improve strength or power performance, it may improve range of motion, which is key for many athletes. Also, there is no clear evidence that static stretching prevents overall injuries, but many experts believe it may reduce the risk of muscle injuries.